Not sure how many Psycho-killers (qu'est-ce que c'est?) are on the board these days, but Gearbox is doing some sort of in game shoot-n-loot. They were supposed to roll out yesterday, but due to technical difficulties are starting today @ 11am EST. http://www.borderlands2loothunt.com/ I think they're staggering things so you could (in theory) start a new character and run through the full 4 weeks since the first target is Knuckledragger.
I really liked BL2... The only class I played as was the Commando. Wouldn't mind playing as the Assassin or Mechromancer again.
The hunt seems to be a progression through every boss. I just started a gunzerk since I never played one and doing each daily mission will net perfect guns to level up with. I actually really dig the siren, she's great in MP and can take down badasses easy with phaselock